Cyclone strikes healthiest part of Great Barrier Reef

For two years in a row, the Great Barrier Reef in Australia is undergoing a bleaching process caused by warm waters.

And for the second year in a row, the findings are grim: Severe bleaching occurred on numerous individual reefs in the middle third of the 2300-kilometer-long system, according to the aerial survey results released today.

While last year's bleaching hit mainly the northern section of the reef, the latest damage is reported to have occurred in the middle section.

Researchers estimate that it would take even the fastest growing coral about a decade to recover - but that would require a year or two without any bleaching to give the corals an opportunity to regrow.

Prof Hughes, who undertook the aerial surveys in both 2016 and 2017, said the bleaching was caused by record-breaking temperatures driven by global warming.

Great Barrier Reef coral bleaching composite map shows surveyed coral reefs in 2016 (left panel) and 2017 (right panel).

"Bleached corals are not necessarily dead corals, but in the severe central region we anticipate high levels of coral loss".

This is the fourth time coral bleaching has hit the reef after previous events in 1998 and 2002.

The intense, slow-moving system was likely to have caused varying levels of damage along a path up to 100km in width.

"The water is just too damn hot", says Terry Hughes, the leader of the survey, who fears that climate change is creating a new norm that corals are unable to endure.

As well, they predict any ocean cooling effects related to the cyclone are "likely to be negligible in relation to the damage it caused".

The ARC assessed nearly 800 coral reefs over an 8,000km area for its survey. "Without a doubt the most pressing of these is global warming". Researchers have recorded serious coral blanching crosswise over tremendous tracts of the Great Barrier Reef in the wake of finishing ethereal overviews along its whole length.

James Kerry, a senior research officer at the ARC said the damage was unprecedented.

Image credit: The Huffington Post."The data are truly daunting", said Robert Richmond, a coral reef expert, and director of the University of Hawaii's Kewalo Marine Laboratory.

Last year, it was the El Niño phenomenon the responsible for the massive bleaching suffered by the reef. As temperatures continue to rise the corals will experience more and more of these events: "One degree Celsius of warming so far has already caused four events in the past 19 years", Hughes added.

'Ultimately, we need to cut carbon emissions, and the window to do so is rapidly closing'.

  • Carolyn Briggs